Apparatus for making building blocks



March 17, 1936. J. N. VAN KAMERIK APPARATUS FOR MAKING BUILDING BLOCKS Filed Jan. 19, 1955 Inventor: John N.Van Kamerik, by w. At or ey.

Patented Mar. 17, 1936 U N TE STATES PATENT OFFEQE APPARATUS FOR MAKING BUILDING BLOCKS Application January 19, 1935, Serial No. 2,546

4 Claims.

The present invention relates to the fabrication of building blocks from moldable material, such, for example, as concrete mixtures, and in particular to the fabrication of molded blocks or 5 the like which are made by the use of insufficient water to permit of the mixture being formed by casting or pouring into a mold.

It is the object of my invention to provide an apparatus for fabricating pressure-molded or tamped block having thereon, as an integral part of the block, a facing layer of material unlike the molding mixture, such, for example, as a facing of crushed metaphorphic rock (such as crushed granite). Such a facing layer gives to the block when laid in a Wall the appearance of a quarried stone. In a divisional application Serial No. 54,274, filed December 13, 1935, I have claimed a method of making building blocks involving the incorporation of a preformed facing layer in a semi-dry, tamped concrete block so as to produce a unitary structure.

Heretofore, it has been considered practicable to fabricate such faced blocks only by a casting or pouring process, whereby a concrete mixture containing enough water to permit pouring is cast in a mold against or upon the desired facing layer.

When blocks thus made are to be provided with passages, or hollows, then collapsible cores are placed in desired position in the molds. These cores are collapsed and withdrawn from the cast blocks when they have become sufficiently hard and self-supporting by the setting of the cement in the concrete. This procedure requires an expensive mold equipment as each mold with its 39 cores, when the fluid concrete has been cast therein, must await the setting of the concrete before another block can be cast in the same mold. The setting step ordinarily requires about twenty-four hours, even when the setting process is hastened by steam curing. This casting process also entails considerable hand labor, and is wasteful of space.

Concrete blocks have been fabricated more conveniently and at lower cost by a tamping process from a mixture containing too little water to permit casting,--say, less than about six per cent of water. By this so-called semi-dry process building blocks, or other desired concrete articles, are made by feeding a damp mixture of concrete into a mold and progressively tamping, ramming, or pressing, it into coherent form. The product finally is sufliciently self-supporting to permit of its removal from the mold for curing, thus permitting the mold to be used continuously instead of tying it up during the setting or curing step. It was found, however, that. when carrying out this semi-dry process it was not practicable to incorporate a surface layer of granular material in the molded block during the molding step. While attempts have been made to provide the blocks with a facing layer after molding, such semi-dry process blocks have commanded a lower price in the market. The facing layer tends to flake away from the block.

In accordance with my invention I have pro- 10 duced an apparatus whereby a desired granular surfacing layer may be permanently made an integral part of a semi-dry process concrete block.

While the novel features of my invention will be pointed out with greater particularity in the 5 appended claims, attention is called at this point to the following steps in the fabrication of concrete blocks for which my improved apparatus may be used.

(1) In the molding of the semi-dry process 20 concrete mixture a mold is employed having a false or removable side wall which is coated with the desired surfacing material and against which the semi-dry concrete mixture is compacted or rammed. The present invention comprises an 25 apparatus for carrying out this step.

(2) Upon removal from the mold, the formed semi-dry block with the coated false plate adhering thereto is turned (while being held intact from disintegration) into a position in which the block rests upon said surfaced plate, thereby subjecting the surfacing material and the molded concrete to pressure during the setting or curing period.

(3) By the simple expedient of carrying out the setting or curing of the cement in the concrete While the green block rests upon said surfaced plate, the surfacing material is integrally united with the block.

(4) As a final step the metal plate is removed from the finished article, the removal commonly occurring automatically during the storage of the block.

In the accompanying drawing illustrating my invention Fig. .l is a top view of a mold, (shown in part broken away) Fig. 2 is a vertical section of the mold taken on the plane indicated by dot ted lines and in the direction indicated; Fig. 3 is a perspective of a mold plate shown partly coated with crushed stone; Fig. 4 is a perspective view of an ejector plate or pallet for removing the block from the mold; Figs. 5 and 6 are side views of successive steps in fabrication of the molded block to bring the surfacing plate in pressure relation to the block; Fig. '7 is a perspective view of a tilting cradle used in tilting the blocks as shown in Figs. 5 and 6; and Fig. 8 is a perspective view of a finished tamped or pressed block having a facing surface as an integral part in accordance with my invention.

Referring to Figs. 1 and 2, the mold here shown as illustrative of apparatus embodying my invention has side walls I, 2, 3 (4 being broken away) and cores 5, 6 whereby hollows are formed in the block (see Fig. 8). Adjacent one of the side walls, as best shown in Fig. 2, is a removable false plate 8 which is provided with a flange 9 for engaging With the top of the mold. Before being placed in the mold, the plate 8 is coated with a layer 8 of adhesive, such as ordinary glue, then is coated while sticky with comminuted surfacing material H), such, for example, as granular feldspar or granite. It finally is dried. This false plate with the preformed layer of surf-acing material applied thereto is coated with a suspension in water of Portland cement, or other binding agent immediately preceding the molding step. When in position in the mold, thus coated with wet cement, indicated as a layer H, the so-called semi-dry concrete mixture (which actually is damp enough to be pressure-molded) is tamped into the mold by the tamping device 2, which preferably is power operated by suitable apparatus (not shown).

Upon completion of the molding or tamping step, the green molded block is ejected by a power-operated plunger or ejector. On the ejector are mounted pins 13, indicated broken away in the drawing, which act on a pallet M, for ejecting the block from the mold. As shown in the drawing the pallet l4 engages with the plate 8 as well as with a block which is formed in said mold and has openings through which the cores 5, 6 extend when the pallet ejects the molded block. The connected power means for ejecting the molded block have been omitted for the sake of clearness in the drawing, such means being well known. The damp, freshly molded block next is received by a cradle l5 which is rotatable upon the fulcrum l5. As shown in Fig. '7, the cradle consists of two L-shaped angle iron strips I7, 58 connected by two bracing plates [9, 26. Between the face plate 8 and the vertical side of the cradle is placed a support 2! having feet 22. While the block is resting on the pallet M as shown in Fig. 5, the cradle is revolved through an angle of 90 to cause the block to rest upon the coated false plate 8, which in turn rests on the support 2| in the position shown in Fig. 6.

The green molded block then is picked up (by hand or otherwise) while resting on the plate 8 and on the support 2!. The pallet I4 is removed and the block is transferred to a curing chamber (not shown), the block still resting on the plate 8 and being pressed to the facing layer on this plate by gravity. In the curing chamber the blocks are subjected to low pressure steam for about five or six hours. They may remain in the curing chamber for a longer time subsequent to the steaming step to complete the curing and preferably should be kept moist and warm during this step. They are finally transferred to the storage yard exposed to the weather.

The false plates come 01f automatically after the steaming and setting step as during the curing and setting step the glue loses its adhesiveness and the metal plate separates from the finished block. The preformed facing layer It] becomes an inseparable part of the cured concrete block 25, shown in Fig. 8, due to the effect of pressure applied both during the molding and the curing steps. As. a consequence of my invention a superior article is fabricated at a lower cost than is possible by the wet or casting process.

What I claim as new and desire to secure by Letters Patent of the United States is:

1. An apparatus for fabricating molded articles comprising the combination of a mold, a separable metal mold plate constructed to engage with the top of said mold in contact with a side wall of said mold, and a pallet engaging with the a bottom of said plate and being adapted to eject from said mold an object formed therein together with said plate while maintaining said parts in undisturbed relation to one another.

2. An apparatus for molding semi-dry concrete mixtures comprising the combination of a mold having longitudinally extending cores located therein, a fiat plate having a flange angularly extending from one end thereof whereby said plate may be supported from the top of said mold adjacent a side wall thereof and in substantially parallel relation to said cores, a pallet formed and arranged to move in said mold in engagement both with said plate and a molded object formed therein and power operated means acting on said pallet to eject from said mold said object and plate in undisturbed relation to one another.

3. A molding apparatus comprising the combination of a mold receptacle, tamping means for compacting a charge in said receptacle into coherent form, a separable metal sheet constructed to be supported longitudinally in said receptacle adjacent a wall of said receptacle clear of its bottom, andwhereon a layer of bonded granular material may be held in position to be incorporated into an object which is formed in said receptacle by said tamping means, a pallet arranged to move longitudinally in said receptacle and being constructed to engage with said sheet support and such molded object and means acting on said pallet for ejecting from said receptacle a formed object in undisturbed relation with said support and the bonded layer held thereon.

4. An apparatus for molding semi-dry concrete mixtures comprising the combination of a mold, a separable mold plate constructed to be capable of support from the top of said mold adjacent a side wall thereof and in substantially longitudinal position in said mold, and a pallet constructed and arranged to be movable longitudinally in said mold for ejecting said plate and a molded object formed in said mold in undisturbed relation to one another, whereby a preformed facing layer on said plate may be held in position to be incorporated into the surface of such molded object.

JOHN N. VAN KAMERIK. 

